You're quite right in many respects mate. However the 'ticking' shouldn't get confused with the noise associated with injector tick or a lazy tappet - that's a really light tick.
A member on MEG has had the latter for the last 10K miles and is well serviced by a Ford dealer. The master tech there has worked on the DuraTec-6 since they were first introduced and assured him yonks ago that it was really nowt to be worried about.

His 200 has 130K miles under its belt now and still feels well tight and pulls like a train... Low or high miles, it's down to how it's looked after & serviced that yields longevity out the engine and the rest of the car imo; so that's what you should be looking for matey

Clearly if it's more than what I describe then go with what ^^^^^ says and walk away